In the preparation of prior art aerosol and pump spray hair care formulations, pure (100%) alcohol has, heretofore, been the primary solvent of choice utilized in consumer "pump" hair sprays to deliver the product onto human hair for hair control and cosmetic appearance. Discussions of such products appear in Cosmetics: Science and Technology, Balsam and Sagarin, 2nd Ed., Vol. 2, 352-358, and Hair and Hair Products, Society of Cosmetic Chemists Continuing Education Program (held in Los Angeles, Calif., Feb. 3-4, 1992) which are incorporated herein by this reference hereto.
Hair spray is a styling and beautifying aid used by 65% of women over thirteen. Seventy percent of these women use hair spray daily. Consumers require hair sprays to perform in holding their hairstyle and also to contribute to beautifying the appearance of their hair. People who perm and color their hair are also concerned that the hair spray will not dull the color of their hair or weigh down their curls. Consumers are also conscious of environmental issues and expect their products to comply with regulations without sacrificing performance.
Good holding power is perhaps the primary attribute a consumer looks for in a hair spray. Curl retention under conditions of changing humidity, especially changes to a higher humidity, is critical to the performance of a hair spray. Good curl retention in chemically damaged hair is important since the hair fiber is weakened by the chemical process and will be less likely to maintain the curl. In addition, the hair spray must be capable of being washed out of the hair with shampoo and it must not build up on the hair over successive use. The consumer also requires the hair spray to perform as a beautifying agent. It is expected to contribute positively to the appearance of the hair. Improved shine and luster are some properties a consumer expects. Therefore, a careful equilibrium between ingredients must exist to provide superior hold, be rinsable without buildup, non-flaking, and yet provide shine and manageability.
Hair sprays are similar in their basic ingredient content. They contain solvents, a synthetic polymeric resin, a base to neutralize the resin (especially when the resin is a carboxylic acid containing resin), plasticizers and in some cases a surfactant and a fragrance. The resin is the primary ingredient responsible for the curl retention characteristics. The neutralizer contributes to the resin's film properties and also to the resin's solubility or wash out property. Surfactants improve the spreadability of the resin on the hair surface. Plasticizers are added to provide less brittle films, minimize flaking and to maximize shine and curl retention. Hair sprays differ from each other by the type of resin(s) and neutralizer used, the degree of neutralization of the resin, and the use of various types of plasticizers and surfactants. The blending of these ingredients is important in order to obtain and maximize desired properties in the consumer product.
Three types of hair sprays are on the market today; pump hair sprays, hydrocarbon aerosols and carbon dioxide aerosols. Pump hair sprays and hydrocarbon aerosols comprise the majority of the market sales. The predominant solvent system in all three types of hair sprays is alcohol. New regulations require the alcohol level to be limited to a maximum content of 80% in current and new products in an effort to reduce volatile organic compounds (VOC's) at ground level which form ozone through a photochemical reaction with nitrogen oxides in the presence of sunlight.
In response to consumer and environmental needs, we have developed three pump hair sprays that fulfill consumers high expectations in performance while meeting strict standards for reduced air pollution.
Active ingredients found in the prior art hair spray formulations include: a fixative resin such as octyl acrylamide/acrylates copolymer octylacrylamide/acrylates/butylaminoethyl methacrylate copolymer and the like; neutralizing agents, especially desirable when the fixative resin is an acrylic acid, such as sodium hydroxide, aminomethylpropanol (AMP), triethanolamine and the like; solvents including water and alcohols; propellants such as hydrocarbons and the like for aerosol products; plasticizers such as dimethyl silicone, triethyl citrate and lanolin derivatives; and other optional ingredients such as perfumes, coloring agents and pH adjusters depending on the properties desired in a final formulation.
Given that silicones in a synergistic combination with other specially preselected ingredients is a salient feature of the present invention, and that silicones have been employed in prior art hair sprays, it is essential to understand the diverse roles such compounds may play in the hair spray art. A key review of this aspect of the art is found in Hair Fixatives--benefit from the physical and chemical properties of silicones. Christine M. Handt, Soap/Cosmetics Soecialties. October 1987 wherein is reported that different silicones, in diverse concentrations can provide a variety of benefits to hair fixative systems, including softer feel, shine and better curl retention.
The "pump" hair spray products of the prior art contain 100% alcohol as the solvent/carrier. However, this can no longer be. standards require that the alcohol content of such products cannot exceed 80% beginning Jan. 1, 1993 (See: Product Standards for Hair Sprays, California Clean Air Act).
Many researchers are engaged in the hunt for a replacement formulations of pump hair sprays which will be environmentally safe and yet functionally acceptable to the consuming public. However, problems arise when water is used to either replace alcohol or to reduce the alcohol to the mandated content of less than 80%. Because the products created thus far leave hair flat and dull, require excessive drying time, promote increased tackiness and exhibit substantially weaker holding power for curls.
Obviously, the problems involved in adding relatively small amounts of water, approximately 15% of the solvent system, to a pump hair spray are very significant. The reason is that water greatly affects the physical properties of the fixatives.
The ultimate product, heretofore unattainable, should provide: a hair control spray which can be delivered by a pump spray which will contain less than 80% alcohol solvent; which will provide cosmetically acceptable curl retention; low tack and drying time; better rinse-out and little or no flaking; high shine (luster); and a crystal clear formulation which yields a clear dried film.